1. Field of the Invention
The present general inventive concept relates to an image forming apparatus, and more particularly, to an image forming apparatus having an array printhead formed with a nozzle unit having a length that corresponds to a width of a printing medium.
2. Description of the Related Art
An inkjet image forming apparatus is an apparatus for ejecting ink to form an image using a shuttle type printhead spaced apart from a front surface of paper and performing a reciprocating motion in a direction perpendicular to a feeding direction of the paper. The printhead includes a nozzle unit where a plurality of nozzles that eject ink are formed.
Recently, attempts are being made to achieve a high-speed printing using a line type printhead having a nozzle unit of a length that corresponds to a width of paper instead of a printhead that reciprocates in a width direction of the paper. In the above inkjet image forming apparatus, since the printhead is fixed and only paper is delivered, a driving mechanism is simple and a high-speed printing may be achieved.
FIG. 1 is a cross-sectional view illustrating a conventional printhead.
Referring to FIG. 1, a body 1 formed of ceramic material includes a mounting part 3 in which a manifold 2 may be mounted. The manifold 2 includes a space through which ink is supplied. The manifold 2 includes one inlet port 4 and two outlet ports 5 and 6, which are located with a predetermined interval so that ink may flow therethrough. Ink that enters through the inlet port 4 flows to an ink cartridge (not shown) through the outlet ports 5 and 6, so that ink circulates.
A nozzle unit 7 having a plurality of nozzles (not shown) is attached on one side of the manifold 2 and a printed circuit board (PCB) 8 is attached on the other side (i.e., the opposite side) of the manifold 2. The nozzle unit 7 is electrically connected to the PCB 8 to eject ink under the control of the PCB.
To form a color image, the conventional printhead has a structure where four manifolds 2 are mounted with a predetermined interval in the body 1. The manifolds 2 supply ink of colors Y (yellow), C (cyan), M (magenta), and K (black), respectively, to allow the ink to be ejected to an outside of the printhead through the nozzle unit 7, so that the color image is formed.
However, a size of the body 1 formed of ceramic material is excessively large and the manifold 2 for supplying ink within the body 1 are formed of metal such as aluminum, so that manufacturing costs increase. Also, since a planarization degree of the body 1 should be managed for attachment of the nozzle unit 7 thereon, additional processes of locating a Ni-plate on the manifold 2 and then attaching the nozzle unit 7 to the manifold 2 are required, which increases the manufacturing costs.